Copper base alloys



July 12, 193s.`

GOPPR BAs ALLoYs Filed June 12, 1.936

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A ORN Patented July 12, 1938 UNITED STATES PATENT or-FlcE corri-:a misa ALLoYs Application June 12, 1936,'seria1 No. s4,sss

6 Claims.

This invention relates to alloys and more particularly to copper base alloys of improved characteristics.

An object of the invention is to provide a high quality copper base alloy of inexpensive ingredients.

A further object is to provide an alloy, the physical properties of which can be improved by heat treatment.

An additional object is to provide an alloy which can be easily cast.

Other objects of the invention will be apparent from the following description taken in connection with the appended claims.

The present invention comprises the combination of elements, methods o'f manufacture, and the product thereof brought out and exemplied in the disclosure hereinafter set forth, the scope of the invention being indicated in the appended 2o claims.

lWhile a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the combination of elements 25 without departing from the spirit of the invention.

The invention may be better understood from the following description when read in conJunction with the accompanying drawing in which:

Figure l is a graph illustrating the improvement in hardness of the alloy disclosed herein with heat treatment; and

Figure 2 is a graph illustrating the improvev ment in electrical conductivity of said alloy with 35. h eat treatment.

vWe have found that by adding manganese and phosphorus to copper or to alpha alloys of copper an intermetallic compound of manganese phosphide can be formed which has a variable 40 solid solubility in the copper matrix. We have,

` therefore, been able to produce copper alloys containing these ingredients which may be greatly improved in hardness and electrical conductivity by a suitable age-hardening process.

The ingredients used are very economical and have been found to introduce no serious diillculties in manufacture. The alloy can'be produced by any of the standard manufacturing methods. For example, it is possible to add the manganese 50 .in the form of cupro-manganese. The phosphorus may be introduced in a standard manner such. as a. 15% phosphor-copper hardener alloy.

The proportions of manganese and phosphorus 55 may each be varied over a considerable range of values and there may be an excess of either in some instances without deleterious effects on the alloy. A suitable ratio of phosphorus to manganese is 1 to 4. However, considerable age hardening is obtained with a ratio of 1 to 2 and 5 also with a ratio as high as 1 to 20.

A slight excess of phosphorus above the amount required to form the intermetallic compound of manganese phosphide with the manganese will ordinarily serve as a deoxidizing agent during the 10 production of the alloy.

As previously stated the manganese phosphide is suitable as a hardening ingredientl for copper or the alpha alloys of copper. Additional ingredients may likewise be added in some instances 15 to produce certain beneficial effects.

Where the manganese and phosphorus are added to substantially'pure copper the ingredients may be present in'the following ranges of proportions:l

Manganese 0.05% to 10% Phosphorus 0.05% to 5% Copper balance The most suitable proportions, however, will fall within the following Manganese 0.4 to 5.0% Phosphorus 0.1 to 0.75% Copper balance Where alpha alloys of copper are used or where the other additions are included, the proportions of manganese and phosphorus may preferably be substantially the same as given above.

In the production of the alloy and the subsequent treatment thereof to improve the electrical, mechanical and thermal characteristics the following procedure may suitably be followed:

After the alloy has been produced it may be heated to a relatively high temperature, preferably in the order of 800 C. to 1000* C. and then 40 rapidly cooled from that temperature to room temperature or below, preferably by quenching in water. After the quenching operation the alloy, in such form as may be desired, may be given an aging treatment by baking at a temperature below '700 C. and preferably at a temperature in the order of 350 C. to 550 C. The aging may proceed for a considerable length of time according to the temperature used. The greatest improvement in hardness and electrical conductivity will be obtained during the flrst two or three hours if 450 C. is used as aging temperature but further improvement may be noted upon continuing the aging for 8 to 16 hours or more.

The improvement in hardness and electricalv conductivity during aging is shown in the graphs (Figures 1 and 2) for certain alloys made according to the present invention. Curves Il, Il, I2

5 and I3 represent the improvement in characteristics of an alloy containing 0.5% manganese, 0.28% phosphorus and the balance copper. It will be noted that this alloy has a ratio of phosphorus to manganese of approximately 1 to 2.

In Figure l the curves I0, H and I2 represent the increase ln Rockwell B hardness of specimens quenched from 900 C., 950 C. and 1000 C. respectively. It will be noted that in all cases the hardness was increased from between 30 and 40 Rockwell B immediately after quenching to between 70 and B0 Rockwell B after aging for 5 to 10 hours at 450 C. y

Further aging at this temperature did not materially affect the hardness of the alloy, but as will be noted from curve I3 of Figure 2, the electrical conductivity steadily increased during aging for 16 hours or more.

It will be noted that the-conductivity increases from about 23% immediately after quenching 25 from 950 C. to 38% after I16 hours aging at Curve Il in Figure 1 represents the increase in hardness obtained during aging in specimens of an alloy containing 3.65% manganese, 0.18%

phosphorus and the balance copper. 'I'his alloy has a ratio of phosphorus to manganese of 1 to 20.

The alloy of the present invention is very economical to produce and results in a material of high strength, high hardness, good electrical and heat conductivity and high resistancefto 'corrosion. Y

The material can be easily forged. It can also be extruded and drawn to high hardness and in this respect it is superior to the silicon bronzes 40 used at present.

The alloy is superior to the present phosphor bronzes because it can be heat treated. It likewise has a higher creep strength than phosphor bronzes and will not be so readily softened by exposure to elevated temperatures.. This makes it possible for the alloy to be soldered without losing its strength.

Because of its high strength, good conductivity and high resistance to heat softening the alloy is well suited for use as resistance welding electrodes and dies, soldering iron tips, springs and electric current carrying parts.' There are many init well suited for gas welding and arc welding rods.

Because of its high resistance to atmospheric attack and also to salt water corrosiom'it is suggested as suitable for many marine applications.

While the present invention, as to its objects and advantages, has been described herein as carried out in specific embodiments thereof, it is not desired to be limited thereby butit is intended to cover the invention broadly within the spirit and scope of the appended claims.

' What is claimed is:

1. An electric contacting member composed of about .05 to 10% manganese, 05 to 5% phosphorus and the remainder copper.

2. An electric contacting member composed of about .05 to 10% manganese, .05 to 5% phosphorus and the remainder substantially all copper characterized by high strength and hardness, good electrical and heat conductivity and high resistance to softening at elevated temperatures.

3. An electric contacting member composed of about 0.4 to 5% manganese, 0.1 to 0.75% phosphorus and the balance copper. Y

' 4. A resistance welding electrode composed of about .05 to 10% manganese, .05 to 5% phosphorus and the remainder copper.

5. A resistance welding electrode composed of about .05 to 10% manganese, .05 to 5% phosphorus and the remainder substantially all copper characterized by high strength and hardness, good electric and heat conductivity and high resistance to softening at elevated temperatures.

6. A resistance welding electrode composed lof about 0.4 to 5.0% manganese, 0.1 to 0.75% phosphorous and the balance copper.

FRANZ R. HENSEL. EARL I. LARsEN. 

